More elusive than the Lost Ark and more mysterious than the Great Sphinx is CAPTCHA, that obfuscated string of letters and numbers Internet users must replicate to prove their humanity and gain access to sites commonly trolled by Internet robots.

You try. You fail. You refresh. Or maybe, like many users confronted with this tedious task, you prove too human to bother.

Enter Are You a Human's PlayThru, a series of quick, visually intuitive games, such as "build-the-burger," designed to keep humans amused and bots confused. AYAH is one of several companies, among them Confident Technologies and SolveMedia, providing an alternative to CAPTCHA's annoying hieroglyphics.

Tyler Paxton founded the company in late 2010 with co-founders and fellow University of Michigan MBAs Reid Tatoris and Benjamin Blackmer. The founders say inspiration came when Paxton witnessed a co-worker attempting to buy tickets to a Hannah Montana show for his daughters and ending up foiled by bots who stormed the site, buying up all tickets within moments.

The opportunity for AYAH, according to Blackmer, lies in reinventing a tool that often does not halt the infiltration of bots and consistently alienates human users.

With guidance from advisor Satinder Singh, director of the University of Michigan's Artificial Intelligence Lab, the team learned to think like the bots themselves and developed a product that avoids the common security pitfall of CAPTCHA alternatives, which focus on one single, learnable action. Blackmer explains, "What we've done with PlayThru is build a platform that analyzes interaction, but doesn't require a specific type of interaction to do so."

Through testing and use of gameplay data such as starts, stops and false positives the team determines which games perform best and adjust accordingly. "What differentiates us in the market is our usability perspective," he says. "The best way to grow is to make advocates of your customers. They talk, we listen."

The company also applies this strategy to acquiring users, emphasizing ease of installation and customer support. They offer plugins, libraries, and integration options for WordPress, programming languages like PHP and the open-source content management system Drupal. AYAH rotates developers through customer support, providing them with firsthand knowledge of technical issues that they use to refine the product.

AYAH received $750,000 in financing by lead investment partner Detroit Venture Partners as well as First Step Fund and the Frankel Commercialization Fund in 2011. A beta version of PlayThru launched in January 2012 and as of this spring the company has 5,000 sites, from personal blogs to business, news and gaming sites, running approximately 66 million games per month.

AYAH plans to make money through sponsorships and will offer branded games for free to users. The company is currently seeking advertisers and expects to post revenue from sponsored games this summer. Sites who'd prefer other options can purchase subscription packages ranging from $19 to $299 per month for ad-free games that offer additional features or games that are customized to their own brand.

AYAH's PlayThru was built to optimize responsive design, meaning it can detect the user's device and offer the most effective viewing and navigation. This helps set the company apart from its competitors, according to Tim Kadlec, independent web developer and author of Implementing Responsive Design since "a real challenge most [gamified CAPTCHA alternatives] face is how to be accessible and functional not only on a desktop, but also on smaller screens."

AYAH is housed in Detroit's renovated M@dison Theater Building. While DVP's backing did not require AYAH to set up shop in Detroit, the team had tactical reasons to do so, including a close-knit community that fosters team longevity and loyalty. Those commodities are less in evidence in other start-up incubator cities, they say. And the location sets them apart, says Blackmer. "People remember us as ‘that start-up from Detroit,' because there aren't 2,000 more like us."